1. Field of the Invention
The present invention relates generally to medical instruments and, more particularly, to apparatus and methods for applying and tying surgical thread within a limited workspace.
A variety of diseases, including many which previously would have required surgery, may be diagnosed and treated through medical scope-type instruments. Fiberoptic endoscopes are representative of these devices. Using an endoscope, a physician may confirm the presence of lesions found by other diagnostic methods as well as reveal some that would be missed. Endoscopes are typically introduced into a body orifice (e.g., the mouth or anus) and then advanced to the region of interest. Some scopes, such as laproscopes, are introduced through a small incision overlying the region of interest.
Since scoping instruments are introduced percutaneously or through a small puncture wound, they are less invasive than conventional surgery. In particular, a large incision for exposing a body region is not required. Thus, a patient is spared the morbidity and expense of major surgery. Furthermore, the instruments often cause minimal discomfort, and many procedures can be performed on an outpatient basis.
In addition to the diagnostic value from the direct visualization of an organ or body region, a variety of therapeutic procedures may be performed through an endoscope. Polypectomy and stricture dilation, for example, are routine endoscopic procedures. Other examples include laser ablation and electro-coagulation and cutting. Of particular interest to the present invention is endoscopic surgery, i.e., performing operative procedures through an endoscope.
Basic to any surgical technique, including endoscopic surgery, is the ability to coapt or "close" tissue. Tissue is usually coapted or approximated with surgical thread or suture by sewing together opposing edges. The suture is secured by tying knots at selected locations.
Without special instruments, knot tying is at best a bimanual task. Usually a knot is tied by holding one end of the thread while the other hand passes the opposite end of the tread under (or over) the first end. Alternatively, a loop may be formed on one end and slipped over the other end; this "slip knot" may then be advanced towards the tissue. A grasping instrument (e.g., a needle holder or a hemostat) may be used to facilitate the handling of thread, particularly fine or delicate thread, but two hands are still required. Single-handed techniques (e.g., staples, clips, tapes, and the like) are known for approximating tissue; nonetheless, two-handed sewing or "suturing" remains the most popular technique for closing surgical wounds.
Suturing techniques have not been well adapted to endoscopic surgery however. In contrast to an open surgical field in which a surgeon typically operates, the workspace available to an endoscopist (e.g., the lumen of a viscus) is typically located at a remote site within the body, often with very little room within which to work. Furthermore, operative techniques, including tissue coaptation, must be accomplished through one or more endoscopic ports or cannulas, which afford very little room for maneuvering. Thus, many procedures, including those which require bimanual dexterity such as knot tying, are not readily performed through an endoscope.
Therefore, it is desirable to provide improved apparatus and methods for applying and securing surgical thread within a remote and/or confined workspace. The apparatus should be able to reach these target locations while requiring minimal workspace. Furthermore, the techniques employed by the apparatus in securing suture should not be cumbersome to perform and should rely on dexterity skills which a surgeon already possesses. The present invention fulfills this and other needs.
2. Description of the Background Art
U.S. Pat. No. 4,641,652 describes an applicator for tying sewing threads, typically through an endoscope. The applicator, which comprises a coil at the end of a shaft, requires that the suture (thread and needle) be placed into the applicator prior to insertion through the endoscope. In operation, the needle must be pulled through the coil of the applicator, making the entire technique fairly cumbersome to perform.
Similar apparatus are known. U.S. Pat. No. 4,760,848 describes a knot-tying instrument having a pair of jaws at a distal end of a tube. The jaws may be used for carrying a surgical needle which is attached to a length of suture. The suture may include a performed loop with a slip knot that allows the suture to be tied by passing the needle back through the loop.
U.S. Pat. No. 4,602,635 describes a surgical knot-tying device comprising a cylindrical rod having an angularly cut end which is used in combination with a cannula; a knot is tied externally and advanced forward to the tissue being approximated.
U.S. Pat. No. 4,923,641 describes a suturing instrument for use in arthroscopic surgery. The instrument, which resembles a conventional grasper and forceps-type microsurgical instrument, includes a hollow tip for engaging tissue to be sutured and a recess for securing a hollow tubular needle. Like the device of U.S. Pat. No. 4,602,635, this device requires a knot to be tied externally and advanced forward to the tissue being sutured.
U.S. Pat. No. 3,871,379 describes a laproscopic needle and forceps for use in combination with two trocars; as with the two foregoing patents, a knot is secured outside of the body and then advanced to a desired location.
The disclosures of each of the foregoing references are hereby incorporated by reference.